A randomized trial of an instructional method was conducted in which school nurses taught children asthma self-management principles and skills, including peak flow monitoring, in 20-min, individual sessions over an 8-week period. Thirty-six children participated. An intervention group of 18 children received the teaching sessions. A control group of 18 children received regular care by the nurses, but no teaching sessions. The sample included 64% boys, 69% African-Americans, and 69% Medicaid recipients. The average age of subjects was 10.2 years. The two groups were demographically similar, but despite random assignment, the control group had a significantly earlier age of onset of asthma and tended to have had more asthma attacks in the preceding year. These factors were statistically controlled in outcome analyses. Results of group comparisons showed no significant differences in the number of postintervention emergency room visits and days absent from school. However, nurses reported that children who practiced breathing exercises had less anxiety during exacerbations, and the nurses' knowledge of the children's baseline peak expiratory flow rates facilitated care of the children. Nurses expressed the opinion that the individual sessions with students might be useful in motivating them to participate effectively in later group sessions. The intervention was well accepted by students, parents, and nurses. We believe that this intervention is promising as a practical, low-cost approach to enhancing children's asthma self-management skills and warrants further testing in a larger sample, with the intervention conducted over a longer period.